Closed-loop control design is nowadays a well-documented and studied domain. Most synthesis methods rely on a linear model of the controlled system to optimise a feedback control law under criteria of stability, robustness, tracking error minimisation and/or disturbance rejection. The underlying linear assumption is the main challenge stated by the transposition of such design strategies to flow control. In particular, the system dimensionality, non-linear response, and simulation cost are issues specific to fluid mechanics. A wide literature proposed adapted methods to design closed-loop control laws with these constraints, as highlighted by [1]}. Among the recent related work, one may cite [2]}, who develop a multi-step method to design controllers, using open-loop responses to forcings and building a reduced-order model of the system.
